Interstate Pneumatics pressure relief valves are ASME certified safety devices which are designed to divert pressure in the event that a pressurized system of some kind encounters a problem which leads to a dangerous rise in pressure. Pressure relief valves are extremely useful and required by law for safety reasons.
Interstate Pneumatics V200-4 is 1/4" MPT with Pull ring having relief pressure of 200 PSI @ 62 SCFM.